To estimate the prevalence and the related risk factors of low bone mineral density of the calcaneus and the distal radius, a community-based study was conducted in three rural areas of Korea. A total of 1420 women and 732 men aged 40 years and older participated in this study. Information on sociodemographic characteristics and the potential risk factors for osteoporosis were collected by an interviewer-administered standardized questionnaire. Bone mineral density (BMD) of the calcaneus and the distal radius were measured by dual-energy X-ray absorptiometry (DXA). Three hundred and seventeen women and 183 men aged 20-29 years who participated in a regular health check-up were used as a reference population. Osteoporosis was defined using WHO criteria. Odds ratios of the risk factors of osteoporosis were calculated by the unconditional logistic regression model. The standardized prevalence of osteoporosis of the calcaneus was 8.4% for males and 27.3% for females using the Korean population of year 2000 as a standard population. The standardized prevalence of osteoporosis of the distal radius was 4.2% for males and 18.8% for females. Older age and lower body mass index (BMI) were related with low BMD in both the calcaneus and distal radius in males and females. The duration after menopause and the number of live births were an independent risk factor for osteoporosis of the calcaneus (OR = 1.1, 95% CI = 1.00-1.11; the duration after menopause; OR = 2.0, 95% CI = 1.20-3.35, the number of live birth) and a familial history of non-traumatic fractures or osteoporosis among the first-degree relatives was significantly related to a increased risk of osteoporosis of the distal radius in females (OR = 2.9, 95% CI = 1.36-6.31).